Integrated circuit manufacturing provides a substantial portion of the electronic components in use today. Although there are many different manufacturing processes for producing a finished integrated circuit, almost all of these processes have certain aspects in common. For example, it is common to fabricate integrated circuits on roughly circular semiconductor substrates, or wafers. Further, it is common to form such integrated circuits so that conductive regions disposed on, or close to, the uppermost layers of the integrated circuits are available to act as terminals for connection to various electrical elements disposed in, or on, the lower layers of those integrated circuits.
Conventional integrated circuit manufacturing processes, typically produce fixed electrically conductive pathways, in the form of lines of metal, metal alloys, or metal laminate stacks. Generally these metal lines are unchangeable by the time a wafer is ready for testing and assembly. In conventional integrated circuit manufacturing processes it is common for terminals, such as those mentioned above to be brought into contact with probes for testing, and further to be contacted with bond wires or solder bumps for connection of the integrated circuit to a package, board, or similar environment.
Probing and testing of integrated circuits while they are still in wafer form can be expensive and difficult. This is a particularly difficult problem for high pin-count integrated circuits.
What is needed are methods and apparatus for lowering the cost of testing integrated circuits that are still in wafer form.